I had same this problem and I found that I have air leak in the air intake boot since I replace it its alright now.

Ugh I wish my problem would of been as simple as that... Unfortunately I checked all my vacuum hoses and all seem fine.

Hopefully someone in here could do a quick check for me and have there MAF disconnected and check voltages for O2 and then reconnect MAF and recheck voltages of the O2 to see if there is any voltage differences.